omap4: suspend: Add basic system suspend support

This patch adds support for basic suspend doing a CPUx wfi
for OMAP4. All powerdomains are for now are kept programmed
in ON state.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

2 files changed, 136 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index 0efcc94fad2f..3cb1b510ee42 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -49,6 +49,7 @@ ifeq ($(CONFIG_PM),y)
 obj-$(CONFIG_ARCH_OMAP2)                += pm24xx.o
 obj-$(CONFIG_ARCH_OMAP2)                += sleep24xx.o
 obj-$(CONFIG_ARCH_OMAP3)                += pm34xx.o sleep34xx.o cpuidle34xx.o
+obj-$(CONFIG_ARCH_OMAP4)                += pm44xx.o
 obj-$(CONFIG_PM_DEBUG)                  += pm-debug.o
 
 AFLAGS_sleep24xx.o                      :=-Wa,-march=armv6
diff --git a/arch/arm/mach-omap2/pm44xx.c b/arch/arm/mach-omap2/pm44xx.c
new file mode 100644
index 000000000000..54544b4fc76b
--- /dev/null
+++ b/arch/arm/mach-omap2/pm44xx.c
@@ -0,0 +1,135 @@
+/*
+ * OMAP4 Power Management Routines
+ *
+ * Copyright (C) 2010 Texas Instruments, Inc.
+ * Rajendra Nayak <rnayak@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/pm.h>
+#include <linux/suspend.h>
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#include <plat/powerdomain.h>
+#include <mach/omap4-common.h>
+
+struct power_state {
+        struct powerdomain *pwrdm;
+        u32 next_state;
+#ifdef CONFIG_SUSPEND
+        u32 saved_state;
+#endif
+        struct list_head node;
+};
+
+static LIST_HEAD(pwrst_list);
+
+#ifdef CONFIG_SUSPEND
+static int omap4_pm_prepare(void)
+{
+        disable_hlt();
+        return 0;
+}
+
+static int omap4_pm_suspend(void)
+{
+        do_wfi();
+        return 0;
+}
+
+static int omap4_pm_enter(suspend_state_t suspend_state)
+{
+        int ret = 0;
+
+        switch (suspend_state) {
+        case PM_SUSPEND_STANDBY:
+        case PM_SUSPEND_MEM:
+                ret = omap4_pm_suspend();
+                break;
+        default:
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
+static void omap4_pm_finish(void)
+{
+        enable_hlt();
+        return;
+}
+
+static int omap4_pm_begin(suspend_state_t state)
+{
+        return 0;
+}
+
+static void omap4_pm_end(void)
+{
+        return;
+}
+
+static struct platform_suspend_ops omap_pm_ops = {
+        .begin          = omap4_pm_begin,
+        .end            = omap4_pm_end,
+        .prepare        = omap4_pm_prepare,
+        .enter          = omap4_pm_enter,
+        .finish         = omap4_pm_finish,
+        .valid          = suspend_valid_only_mem,
+};
+#endif /* CONFIG_SUSPEND */
+
+static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
+{
+        struct power_state *pwrst;
+
+        if (!pwrdm->pwrsts)
+                return 0;
+
+        pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
+        if (!pwrst)
+                return -ENOMEM;
+        pwrst->pwrdm = pwrdm;
+        pwrst->next_state = PWRDM_POWER_ON;
+        list_add(&pwrst->node, &pwrst_list);
+
+        return pwrdm_set_next_pwrst(pwrst->pwrdm, pwrst->next_state);
+}
+
+/**
+ * omap4_pm_init - Init routine for OMAP4 PM
+ *
+ * Initializes all powerdomain and clockdomain target states
+ * and all PRCM settings.
+ */
+static int __init omap4_pm_init(void)
+{
+        int ret;
+
+        if (!cpu_is_omap44xx())
+                return -ENODEV;
+
+        pr_err("Power Management for TI OMAP4.\n");
+
+#ifdef CONFIG_PM
+        ret = pwrdm_for_each(pwrdms_setup, NULL);
+        if (ret) {
+                pr_err("Failed to setup powerdomains\n");
+                goto err2;
+        }
+#endif
+
+#ifdef CONFIG_SUSPEND
+        suspend_set_ops(&omap_pm_ops);
+#endif /* CONFIG_SUSPEND */
+
+err2:
+        return ret;
+}
+late_initcall(omap4_pm_init);